Concurrent languages

Message passing languages provide language constructs for concurrency. The predominant paradigm for concurrency in mainstream languages such as Java is shared memory concurrency based on monitors. Concurrent languages that make use of message passing have generally been inspired by CSP or the ?-calculus, but have had little commercial success, except for Ada and Erlang. Ada is a multipurpose language and concurrent programming is only one option available.

Curly-bracket languages

The curly-bracket or curly-brace programming languages have a syntax that defines statement blocks using the curly bracket or brace characters { and }. This syntax originated with BCPL (1966), and was popularized by C (1972). Many curly-bracket languages descend from or are strongly influenced by C. Examples of curly-bracket languages include:

Dataflow languages[]

Dataflow programming languages rely on a (usually visual) representation of the flow of data to specify the program. Frequently used for reacting to discrete events or for processing streams of data. Examples of dataflow languages include:

Data-oriented languages

Data-oriented languages provide powerful ways of searching and manipulating the relations that have been described as entity relationship tables which map one set of things into other sets. Examples of data-oriented languages include:

Assembly languages that statically link data inline with instructions can also be considered data-structured, in the most primitive way.

Decision table languages

Decision tables can be used as an aid to clarifying the logic before writing a program in any language, but in the 1960s a number of languages were developed where the main logic is expressed directly in the form of a decision table, including:

Declarative languages

Declarative languages describe a problem rather than defining a solution. Declarative programming stands in contrast to imperative programming via imperative programming languages, where serial orders (imperatives) are given to a computer. In addition to the examples given just below, all (pure) functional and logic-based programming languages are also declarative. In fact, "functional" and "logical" constitute the usual subcategories of the declarative category.

Embeddable languages

In source code

Source embeddable languages embed small pieces of executable code inside a piece of free-form text, often a web page.

Client-side embedded languages are limited by the abilities of the browser or intended client. They aim to provide dynamism to web pages without the need to recontact the server.

Server-side embedded languages are much more flexible, since almost any language can be built into a server. The aim of having fragments of server-side code embedded in a web page is to generate additional markup dynamically; the code itself disappears when the page is served, to be replaced by its output.

Client side

In object code

A wide variety of dynamic or scripting languages can be embedded in compiled executable code. Basically, object code for the language's interpreter needs to be linked into the executable. Source code fragments for the embedded language can then be passed to an evaluation function as strings. Application control languages can be implemented this way, if the source code is input by the user. Languages with small interpreters are preferred.

Hardware description languages

In electronics, a Hardware description language or HDL is a specialized computer language used to describe the structure, design and operation of electronic circuits, and most commonly, digital logic circuits. The two most widely used and well-supported HDL varieties used in industry are Verilog and VHDL. Hardware description languages include:

Interactive mode languages

Interactive mode languages act as a kind of shell: expressions or statements can be entered one at a time, and the result of their evaluation is seen immediately. The interactive mode is also known as a REPL (read-eval-print loop).

Interpreted languages

Interpreted languages are programming languages in which programs may be executed from source code form, by an interpreter. Theoretically, any language can be compiled or interpreted, so the term *interpreted language* generally refers to languages that are commonly interpreted rather than compiled.

SQL - has only a few keywords, and not all the constructs needed for a full programming language[1] - many database management systems extend SQL with additional constructs as a stored procedure language

Machine languages

Machine languages are directly executable by a computer's CPU. They are typically formulated as bit patterns, usually represented in octal or hexadecimal. Each bit pattern causes the circuits in the CPU to execute one of the fundamental operations of the hardware. The activation of specific electrical inputs (e.g., CPU package pins for microprocessors), and logical settings for CPU state values, control the processor's computation. Individual machine languages are specific to a family of processors; machine-language code for one family of processors cannot run directly on processors in another family unless the processors in question have additional hardware to support it (for example, DEC VAX processors included a PDP-11 compatibility mode). They are (essentially) always defined by the CPU developer, not by 3rd parties. The symbolic version, the processor's assembly language, is also defined by the developer, in most cases. Some commonly used machine code instruction sets are:

Macro languages

Textual substitution macro languages

Macro languages transform one source code file into another. A "macro" is essentially a short piece of text that expands into a longer one (not too be confused with hygienic macros), possibly with parameter substitution. They are often used to preprocess source code. Preprocessors can also supply facilities like file inclusion.

Macro languages may be restricted to acting on specially labeled code regions (pre-fixed with a # in the case of the C preprocessor). Alternatively, they may not, but in this case it is still often undesirable to (for instance) expand a macro embedded in a string literal, so they still need a rudimentary awareness of syntax. That being the case, they are often still applicable to more than one language. Contrast with source-embeddable languages like PHP, which are fully featured.

Metaprogramming languages

Metaprogramming is writing of programs that write or manipulate other programs (or themselves) as their data or that do part of the work that is otherwise done at run time during compile time. In many cases, this allows programmers to get more done in the same amount of time as they would take to write all the code manually.

Procedural languages

Procedural programming languages are based on the concept of the unit and scope (the data viewing range of an executable code statement). A procedural program is composed of one or more units or modules, either user coded or provided in a code library; each module is composed of one or more procedures, also called a function, routine, subroutine, or method, depending on the language. Examples of procedural languages include:

Reflective languages

Reflective languages let programs examine and possibly modify their high level structure at runtime. This is most common in high-level virtual machine programming languages like Smalltalk, and less common in lower-level programming languages like C. Languages and platforms supporting reflection:

Rule-based languages

Rule-based languages instantiate rules when activated by conditions in a set of data. Of all possible activations, some set is selected and the statements belonging to those rules execute. Rule-based languages include:[]

Scripting languages

"Scripting language" has two seemingly different, but in fact similar meanings. In a traditional sense, scripting languages are designed to automate frequently used tasks that usually involve calling or passing commands to external programs. Many complex application programs provide built-in languages that let users automate tasks. Those that are interpretive are often called scripting languages.

Recently, many applications have built-in traditional scripting languages, such as Perl or Visual Basic, but there are quite a few native scripting languages still in use. Many scripting languages are compiled to bytecode and then this (usually) platform-independent bytecode is run through a virtual machine (compare to Java virtual machine).

See also

References

^The objects of SQL are collections of records, called tables. A full programming language can specify algorithms, irrespective of runtime. Thus an algorithm can be considered to generate usable results. In contrast, SQL can only select records which are limited to the current collection, the data at hand in the system, rather than produce a statement of the correctness of the result.

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Manage research, learning and skills at IT1me. Create an account using LinkedIn to manage and organize your IT knowledge. IT1me works like a shopping cart for information -- helping you to save, discuss and share.